OP0187 COMPARATIVE EFFICACY OF NON-BIOLOGIC IMMUNOSUPPRESSANTS IN TAKAYASU ARTERITIS
Authors: R. Goel, M. Babu, S. Padiyar, G. Joseph, D. Danda
Journal: Annals of the Rheumatic Diseases (2022)

Background The choice of immunosuppressant (IS) in patients with Takayasu arteritis (TAK) is often arbitrary due to lack of comparison studies. Objectives In this retrospective, we aimed to compare the efficacy of 3 non biologic IS including azathioprine (AZA), mycophenolate mofetil (MMF) and methotrexate (MTX) in inducing and maintaining sustained remission in patients with TAK. Methods Patients with a diagnosis of TAK, attending our clinics between Jan 2000 and May 2019 were identified. Those who satisfied either ACR or Sharma’s classification or EULAR PRINTO PRES criteria and/or had angiographic evidence of Takayasu arteritis with a minimum 2 follow up visits were included. Patients who received upfront biologics were excluded. The patients were matched for parameters statistically different among three groups using propensity score analysis. Clinical details at the index visit defined as the time of initiation of first IS and follow up visits were prospectively recorded and retrospectively noted from electronic medical records. The primary outcomes were attainment of complete remission and relapses. Disease activity was assessed by Indian Takayasu arteritis score (ITAS), C-reactive protein and angiograms. Relapse was defined as ITAS-A(CRP) &gt;=2 and/or progression in angiograms and/or escalation of steroid dose and/or switching of IS due to active disease. The baseline variables of patients receiving AZA, MMF and MTX were compared using chi square test or Mann Whitney U test. The comparative efficacy of IS to induce complete remission was calculated using logistic regression and presented as odds ratio (95% CI). The cumulative risk of relapse was calculated using Cox-proportional hazards model with hazards ratio and 95% confidence interval (CI) after adjusting for duration of symptoms and juvenile onset disease. The patients were censored at the time of relapse or time of switching to another IS or last follow up whichever was the earliest. AZA was arbitrary chosen as the reference drug for all the analysis. The missing values (visits) were not included in analysis and the last observation was carried forwards. Data after switching of immunosuppressant of interest till the last follow up visit was analysed descriptively. All analysis were done for matched and unmatched patient groups. The results of matched and unmatched cohort were similar, hence the results of unmatched groups are presented here. Results Overall, 234 patients satisfying inclusion criteria including 53 (22.6%), 156 (66.7%) and 25 (10.7%) patients receiving AZA, MMF, Mtx respectively were studied. Complete remission (CR) was attained in 183 (78.2%) patients after initiating steroids and IS. 79.2%, 77.6% and 80% of patients receiving AZA, MMF or MTX respectively achieved CR yielding an odds ratio of 1.10 (0.52-2.37), p= 0.80 and 0.96 (0.29-3.12), p= 0.94 for MMF and MTX as compared with AZA. CR was sustained in 22 (52.4%), 80 (66.1%) and 11 (55%) of patients on AZA, MMF and MTX respectively. When compared with AZA, adjusted hazards ratio (AHR) of relapse was 1.51 (0.79-2.89), p=0.21 and 2.45 (1.00-5.99), p= 0.05 with MMF and MTX after adjusting for juvenile onset disease, type 1 and type 4 disease by angiography. The frequency of remission in patients who received MMF was significantly higher in patients who presented with type 4 disease (96%) as compared with the patients who had other types on angiography (74%), p= 0.017. Conversely, 63.6% of patients with type 1 disease responded to MMF which was significantly lower than 81.3% of patients with other angiographic types (p=0.037) while no such differential response was observed for AZA or MTX. Retrospective design and small number of patients in AZA and Mtx group were the major limitations of the study. Conclusion In our patients with TAK, all the three IS were comparable in inducing remission. Azathioprine was equal to MMF but superior to MTX in maintaining relapse free sustained response. The efficacy of MMF differed across various angiographic types of disease. References None Disclosure of Interests None declared